A hydraulic excavator, a bulldozer, and the like, each of which includes a crawler belt, have been known as work vehicles. The crawler belt includes a crawler belt link chain in which a plurality of crawler belt links are coupled to one another. When detaching/attaching the crawler belt from/to the traveling apparatus, the crawler belt link chain is decoupled. An exemplary technique of decoupling the crawler belt link chain is to detach a master pin, which connects crawler belt links to each other, from the crawler belt link.
In this technique, when the master pin is pressed into the crawler belt link with interference fit, a pressing machine is required to detach/attach the master pin from/to the crawler belt link. Thus, such a pressing machine is required to detach/attach the crawler belt from/to the traveling apparatus in a work site. This results in poor workability in attaching/detaching the crawler belt in the work site.
For example, Japanese Utility Model Laying-Open No. 64-1078 (Patent Document 1) proposes an apparatus permitting detachment/attachment of a master pin from/to a crawler belt link and including a retaining pin to prevent the master pin from coming off from the crawler belt link. In this structure, the retaining pin is withdrawn/inserted to detach/attach the master pin from/to the crawler belt link without using a pressing machine.
In addition, in this apparatus, a brim is provided at one end of the master pin and the retaining pin is inserted into the other end thereof. Further, the crawler belt link is provided with a locking boss, which is engaged with the brim of the master pin. With the engagement between the brim of the master pin and the locking boss of the crawler belt link, the master pin can be suppressed from being turned according to the crawler belt link.